The present invention relates to a hand-held power tool.
German reference DE 296 01 129 discloses a hand-held power tool which is formed as a screw drilling machine and has a coupling between a drive motor and a tool receptacle for transmission of different torques. The coupling has two coupling parts which are rotation-lockingly connected by transmission members. Balls are provided on one coupling part and engage corresponding arresting recess of the other coupling part. The balls are loaded with an adjustable pre-tensioning force in the engaging direction. The torque transmission between the coupling parts in the engaging direction is performed through transmission surfaces in which the transmission members contact one another. The transmission surfaces are arranged so relative to a rotary direction of the coupling, so that depending on the torque, a force is produced in direction of the disengagement of the transmission members, which counteracts the pre-tensioning force. When pressing out force exceeds the pre-tensioning force, a disengagement of the coupling and thereby an interruption of the rotary transmission occurs.
The known coupling has the disadvantage that with increasing torque, greater pretensioning forces must be provided, which are taken by the coupling parts. In the operational position for drilling in which an overarresting of the coupling is not desired, high pressing-out forces must be taken by the coupling parts, which requires a corresponding design of the hand-held power tool.